Electric signaling.



R. A. FESSENDEN.

ELECTRIC SIGNALING.

APPLICATION men JUNE 16, I908.

1,179,906. Patented Apr. 18,1916.

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WITNESSES IN V EN TOR,

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UNITED STATES PATENT OFFICE.

REGINALD A. FESSENDEN. 0F BRANT ROCK. MASSACHUSETTS. ASSIGNOR. BY MESNE ASSIGNMENTS. TO SAMUEL M. KINTNER. 0F PI'l".l'.SBURGHv PENNSYLVANIA. AND HALSEY M. BARRETT. OE BLOOMFIELD. NEW JERSEY. RECEIVERS.

ELECTRIC SIGNALING.

Application filed June 16. 1908.

To all whom I! may ('OIIIIIII.

lle it ltnown that l. REGINALD F|-:ssr..\' m-:.\'. a eitizen of the l nited States. residing at lirant lloelt'. in the mainly of llvmouth and State of .\lassaehusetts. have invented eertain new aml useful Improvements in l'ileetrie Signaling. of' which the following is a speeifieation.

l v invention relates to the reeeipt and transmission of' eleetrieal signals and more partieularlv to wireless signaling. lts primar v olljet't is a more eflieient transmission and reeeipt of eleetrieal signals. more partieularlv wireless signals. aml the reeording of sueh signals. ()ther advantages and ohjeets will hereinafter appear.

The invention is illustrated in the aeeompan ving drawings forming a part of this speeifieatiou wherein.-

Figures 1 and .2 show res wetivelv in section aml plan a wireless telegraph receiver in whieh motion is used to alter the resistant-e of a mierophonie eell. instead of direetl) producing a sound indication. and Figs. 3 and 1 are respeetivelv a eross seetion and a plan of a form of reeeiver in \vhieh the. static attraetion is used to produce a ehange in the resistant-e of a local mierophouie eireuit. Fig. 3 showing also 21 diagram of eireuits.

l olhear in l. 5. Patent No. 350.299 of 189-2. deserihed a statie telephone receiver. invented hy him for reeeiving wireless signals. and this reeeiver has lieen used h v other experimenters for the same purpose.

In the various forms used the diaphragms have heen made of sheet metal or of sheet metal eovered with an electrified dielectrics or of a dieleetrie with a metallie eoaeting on the side next the fixed plate. 'lhese types of reeeivers have on this aeeonnt heen too insensitive. and have not come into praetieal use.

I have discovered that by the use of eertain improved eonstruetions and improved methods of operation. statie reeeivers ean he made whieh are more sensitive even than the liquid harretter. as determined hy aetual tests under praetieal working eonditions. and l have herein shown several arrangements lrv whieh this result is attained.

In Fig. l. l use two pieees of thin miea 5f aml (it). to whieh are fastened two pieces of platinum foil 61 and (i2. suspended by Specification of Letters Patent.

Patented Apr. 18. 1916.

Serial No. 433.725.

two wires (13 and (it from a terminal (i5. so that when the terminal is eonneeted to an eleetrifieil souree. the flat pieees of platinum foil til and (1;! will he repelled from each other. The depend into a trough ()6 with eleetrodes UT and (is eouneeted to terminals 139 and T0: and the trough eontains a charge of mierophouie earhon 71. ()n the plates til and (r3 heing repelled the resistanee hetween the eleetrodes til and 3H and the pieees of platinlnn foil l and is altered. and afleets the eurrent as in the well-known telephone transmitter. The deviee arts as an amplifier. In Fig. 2 is shown another form of this deviee or amplifier. llere a numlver of pieees of platinum foil T2. ii. are eonneeted to one hinding post. 73. and interleavedtwith a munher of other pieees of platinum foil 74. H eonneeted to a seeond hinding post T5. Between the sets of foil are pieees of sheet miea Tfi. and layers of mierophouie earhon T7. There are also serews TH. 71' for adjusting the pressure of the :nnplifier.

In Figs. 3 and 4 is shown another form of amplifier. llere 1 is a fixed plate mounted so as to he adjustable by means of the milled screw 92. and covered with a coating of nnea 2!. ()u an insulating support H3 is mounted a diaphragm or thin plate 94. and to support 95 is also fastened another plate or spade l ti dipping in a trough 97 having two eleetredes 9 and 90 and filled with a mass of mierophonie earlvon ltltl. .\ttaehed to the insulating piece i are wires W1 and 10;. mounted in frame 10f aml made ad jnstalile as to tension h v means of the knurled nut 10?. (Fig. 4). The eonneetions heiug as per the diagram. Fig. for operation. the eleetrieal waves eause eleetrieal oseillations to flow from the antenna li -3 thr ugh the primary 106 of a transformer to ground at 11-3. therehv produeing oseillations in the seeondarv 107 and the eireuit ineluding also a variahle induetaure 10s. and

a eapaeitv formed hy the plates J1 and 91. The eleetrostatie attraction therehy produeed between these plates sets the plate M in motion and. therefore. also the spade W3. projeeting in the earhon. This varies the resistanee in the leeal mierophonie ireuits eontaining the battery Ina. the primaries Ill and Ill and the mierophonie earlmu l t Electric impulses are. thereby lil 'illiti'tl in the secondary 112 which cause a sound in the telephone receiver 113 in circuit therewith Ha ing thus described my invention and illustrated its: use. what I claim as new and desire to secure by Letters Patent. is the following:

1. receiver for wireless telegraphy com prising a movable miea diaphragm. a plat imnn leaf thereon. a tixed plate statieally attracted by said movable plate. a'mierophonic material between the movable and tixed plates. whereby the motion of the movable plate may be indicated by variation of resistance of said mierophonic material.

2. A receiver for wireless telegraph). eomprising a movable diaphragm, a tixed plate statically attlat'ted by said movable diaphragm, and a microphonie material between said plate and diaphragm. whereby movement of the movable diaphragm 'varies the resistance of the microphonie material.

3. receiver for wireless telegraph). eomprising a movable diaphragm. a iixed plate on either side of said diaphragm and statieally attracted there y. and a microphonie material between said diaphragm and plates. whereby movement of the movable diaphragm varies the resistanee ol' the mierophonie material.

In testimony whereof I have hereunder signed my name in the present-e of the two sllbsel'ibed witnes es.

copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington. D. C. 

